Integrated essay

The reading explains how twins studies help the researchers to find out the role of environment or genetics on people behavioral and physical traits. The lecturer points out some flaws in such research that cast doubt to the underlying idea of it.

According to the professor, in order to recognize the influence of genetic factors on the behaviors and personality of twins, the environment fostering them should be the same. Thus, the pure role of genetic factors will be revealed. This undermines the method of research mentioned in the passage that were carried out on identical twins who were brought up in separated environment.

Furthermore, the professor states that in comparing the degree of behavioral similarity between identical twins and fraternal twins, it is necessary that both pairs of twins experience the same circumstances, such as family, school, and other people behaviors toward them. However, the passage fails to support such similarity in research that compared the personality aspects of identical and fraternal twins.

Finally, the professor contends that people usually tend to consider the identical twins as a unit. In other words, monozygotic twins are treated as if they are one soul in two bodies. Thus, it is more possible that they wear the same cloths or enjoy the same flavor of ice-cream. However, fraternal twins will not be seen this way. This undermines the assumption in the passage that differences between identical and fraternal twins can be attributed to the level of their genetic discrepancy.